The present invention relates to a diaphragm valve with a valve plate which operates together with a valve seat and with a flexible diaphragm formed as a movable valve which separates a housing into two chambers. A fuel injection apparatus for mixture-compressing, externally ignited internal combustion engines with distributor and apportionment valves is already known. In this type of known valve, as a result of the differences in height of the control slits dictated by technical considerations during manufacture, the fuel quantities apportioned to the individual cylinders vary greatly and thus create an undesirable condition. It has been found that the variation in apportioned fuel quantities is particularly great in the idling range, so that there are difficulties associated with the idling adjustment of the motor vehicle engine.